We apply a spatio-temporal Gaussian filter [1]} to each field, which removes the effect of the small-scale convective events.
We define a threshold \(v\) , indicating a large relative wind speed for the filtered data, with relative wind speeds below this level temporarily masked and those that exceed it retained. If the entire filtered wind field is masked, this is interpreted as there being no significant windstorm activity, no footprint is formed and the windstorm is deemed to be in an inactive phase.
